1. Field of the Invention
The present invention relates to cell phone control systems deployed in environments where inhibiting or controlling wireless device communications is desired and further relates to cell phone controllers that inhibit or control wireless mobile communication devices including cell phones, two way radios, smart phones, personal digital assistants, and wireless enabled computers and devices.
2. Description of the Related Art
Wireless communication devices such as cell phones have become increasingly ubiquitous. At times, it is desirable to block or control wireless communications in access areas such as the areas within prison facilities where inmates are housed.
Cell phone controllers are known in the art and are utilized by government agencies with the legal authority to permit or deny usage of the wireless frequency spectrum. Such controllers can operate in a mode where communication is permitted on a select basis based on a cell phones identification numbers or they can operate in a fashion where all cell phone communication is blocked for an entire target area. Another example of cell phone controller operation is where all communication is permitted and the cell phones within the target coverage area are simply identified by the system for later action. Such later action can include a search of the premises for the identified cell phones and/or reporting the identity of the cell phone to the cell phone carriers. Upon receiving a report, contacted cell phone carriers are able to permanently disable a reported cell phone and any associated SIM cards.
Cell phone controllers typically comprise a set of software defined radios interfaced to a processor based control system. The system operates by scanning the ambient wireless environment for signals emanating from nearby cell phone base stations. From the scanning process, the cell phone controller is able to determine the carriers present, the frequencies utilized, and the protocols that are capable of serving the target area. Based on this information, a beacon signal set is created by the cell phone controller. The beacon signal set includes a beacon for each carrier, frequency band, and protocol resident in the target area. A beacon is a signal which is transmitted from a cell phone base station that contains control and identification information from the tower. A beacon which is of the same carrier, frequency band, and protocol which is adequate and sufficiently stronger than the competing beacons in a target area will attract cell phones to register and communicate with the stronger beacon and associated base station or cell phone controller.
Thus, the cell phone controller acts as a multi-protocol, multi-frequency band, multi-carrier base station. This has the benefit of reducing the quantity of equipment needed by combining multiple radios into a single software defined radio and multiple software defined radios into a single system controlled by a single controller. This reduces the cost of such a system greatly. Although the reduction in cost of such a system is beneficial, a method and system to reduce the beacon set required for a given ambient signal environment would have the benefit of further reducing the costs and complexity of deployment.
Cell phone controllers have been described in the prior art that utilize an analog connection to the public switched telephone network or to the resident inmate phone system. Such a connection permits an intercepted cell phone call to be completed by the system by patching the call through to the public telephone network. Although such a connection is helpful, a system that includes a directly connected digital interface in which no analog to digital conversions are necessary would be beneficial in permitting communication to an Internet Protocol (IP) based Private Branch Exchange (PBX) or inmate phone system while at the same time reducing the cost and complexity of the sub-system.
U.S. patent application Ser. No. 13/399,688 (Wireless Communication Device Controller with Improved Coverage Area Control) describes a method in which a cell phone controller is interfaced to a distributed system of antennas in order to confine and control the coverage area. With such a system, it would be beneficial for there to be a method of localizing cell phones that are found within the coverage area. Such a method would be helpful in determining the source of a potential breach in security.